比如想提取20M reads （大约6G）：

命令如下：

/public/home/qtxu/miniconda2/bin/seqtk  sample -s 100 H704-1_RRAS25352-V_1.clean.fq  20000000  > H704_1_v1.fq
/public/home/qtxu/miniconda2/bin/seqtk  sample -s 100 H704-1_RRAS25352-V_2.clean.fq 20000000  >  H704_1_v2.fq

Subsample 20M read pairs from two large paired FASTQ files (remember to use the same random seed to keep pairing):

查看MD5数值

> md5sum checkSize.xls 
1e00e20acfb30a27d4bd64c6a2a25d67  checkSize.xls